TFT LCDs (Thin Film Transistor Liquid Crystal Display) have advantages such as good performance, good property of mass production and wide development space, and become mainstream products in the field of displays nowadays. In the manufacturing process of a TFT LCD, data lines of the liquid crystal display panel may be broken, and thus the quality of the LCD is seriously influenced. In order to solve the problem of disconnection, the broken data line is usually repaired. However, the existing method to repair the disconnected data line usually causes two terminals of the disconnected data line being repaired to have different driving abilities, and then causes uneven luminance of the liquid display panel.